Attachment for alarm-clocks.



E. H. PRATT. ATTACHMENT FOR ALARM CLOCKS.

APPLICATION FILED JAN. a1, 1913.

,ZZ (Fi G lNVEA/TOR ATTORNEYS Patented Mar. 17, 1914.

EDWIN H. PRATT, OF LOMPOC, CALIFORNIA.

ATTACHMENT FOR ALARM-CLOCKS.

Specification of Letters Patent.

Patented Mar. 17, 1914.

Application filed January 31, 1913. Serial No. 745,391.

To all whom it may concern Be it known that I, EDWIN H. PRATT, a citizen of the United States, and a resident of Lompoc, in the county of Santa Barbara and State of California, have invented certain new and useful Improvements in Attachments for Alarm-Clocks, of which the following is a specification.

My present invention relates generally to alarm clocks and is in the nature of a lock for the vibratory hammer and means whereby when the alarm mechanism is wound the lock is automatically released so as to permit unrestricted operation of the vibratory hammer, it being my object to provide such releasing means as may be wholly mounted on the exterior surface of the clock without necessitating ingress or connection within the same, and which is brought into operation by a simple and effective friction clutch member disposed upon an exterior portion of the alarm winding arbor and adapted to engage the same when it is turned in one direction only.

In the accompanying drawing, which illustrates my invention and forms a part of this specification, Figure 1 is a plan view of a portion of an alarm clock provided with my improvements. Fig. 2 is a similar view showing the hammer lock in inoperative position. Fig. 3 is a similar view showing the hammer lock in operative position. Fig. 4 is a detail section through a portion of the mechanism taken on the line 44 of Fig. 2.

Referring now to these figures, I have illustrated a very ordinary form of alarm clock, the time mechanism of which is inclosed within a casing A, the alarm bell B being superposed upon the casing A and mounted on a vertical stem 6, and the vibratory hammer 0 operating within the bell B and having its stem 0 extending through a slot in the casing A. The time mechanism is wound by means of the usual key actuated arbor D and the alarm mechanism is wound by means of the key actuated arbor E.

In accordance with my invention, I mount upon the casing A a movable locking block F having longitudinal slots f through which extend the guide studs G which are connected to the'casing A and thus guide the block F in its movement, the latter being further provided with a laterally projecting knob or handle f by which it may be moved to either a locked position as shown in Fig. 3 and in which its upper end is in contact with the stem 0 of the vibratory hammer C whereby to prevent movement of the hammer, or to a released position as shown in Fig. 2 in which the vibratory hammer is permitted unrestricted operation. Connected at one end of the intermediate portion of the block F is a curved arm H, the lower end of which is provided with an eye it engaged by the eye j formed at the upper end of an arm J, at the lower end of which is formed a coil 7'. The coil j is disposed around the key actuated arbor E of the alarm mechanism and is of peculiar formation, the convolutions thereof gradually decreasing in diameter from the end adjoining the arm J to the opposite end of the coil, the last convolution as clearly indicated in Fig. 4: having a relatively tight frictional engagement with the arbor E upon which it is disposed. Thus with the parts as illustrated in Fig. 3, and the vibratory hammer C prevented from operation, the key actuated arbor E may be rotated in the direction of the arrow as shown in Fig. 2, whereby to wind th alarm mechanism. At the same time the coil y" will be gradually tightening upon the arbor E until a sufiicient grip is created between these parts suflicient to cause downward swinging movement of the arm J which in operation causes lowering movement of the arm H and movement of the locking block F away from the hammer C to the position shown in Fig. 2.

It will'thus be seen that once the alarm clock is wound, it is ready for operation and cannot be prevented from performing its intended functions by mere thoughtless ness in failing to release the hammer look as is the case in clocks of this character now in use.

It is, of course, true that when the alarm is sounded, the arbor E in most alarm clocks is rotated in a direction opposite to that in which it is rotated to wind the alarm, and in view of the fact that this rotation might in some cases reverse the movement of the locking block actuating parts and effect a relocking of the vibratory hammer C, I preferably secure upon the rear face of the easing A an angular spring arm K, the free end it of which extends rearwardly a sufficient distance so as to frictionally engage the arm J in the released position as shown in Fig. 2, such engagement being adapted and effective to prevent a relocking of the hammer as just described.

I claim:

1. The combination with an alarm clock including a casing, an alarm mechanism within the casing and having a winding arbor extending exteriorly of the casing, an alarm bell superposed on the casing and a vibratory hammer operating within the said bell, of a locking block slidably mounted on the casing and movable to a position in contact with the said hammer whereby to prevent the same from vibrating, an arm connected to and extending from the said looking block and provided with an eye at its free end, another arm having an eye at one end engaged with the eye of the first mentioned arm and provided at its opposite end with a coil extending laterally therefrom and surrounding the winding arbor, the convolutions of said coil being gradually reduced in diameter in a direction away from the arm whereby to effect a gradually increasing tension in the engagement of the convolutions with the winding arbor to eilect movement of the locking block away from the hammer to released position, and a spring arm secured to the clock face and extending at an angle therefrom whereby to frictionally engage the last mentioned arm when the block is in released position.

2. The combination with an alarm clock including a casing containing the time and alarm mechanisms, an alarm bell superposed 011 the casing, a vibratory hammer ,operating within the bell, and a winding arbor for the hammer mechanism extending outwardly from the casing, of a locking block slidably mounted on the casing for movement to engage and lock the vibratory 4Q hammer, an operating arm having connection at one end with the said locking block and provided with a coil at its opposite end surrounding and adapted to frictionally engage the said Winding arbor, and means adapted to engage and hold the said arm when moved to release the block from the hammer.

3. The combination with an alarm clock having an alarm mechanism including a winding arbor, an alarm bell, and a vibratory hammer operating within the bell, of a locking block mounted on the clock for movement to engage and lock the said hammer, an operating arm having connection with the said block at one end, and a coil formed upon the opposite end of the said arm, said coil being disposed upon the said winding arbor and adapted for frictional engagement therewith when the alarm mechanism is wound whereby to automatically move the locking block to released position.

EDWIN H. PRATT.

lVitnesses A. M. REED, RONALD M. ADAM.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

